When the teachings of this invention are followed, my prior invention becomes economical and practical in respect to debonding, lifting, and removing ice from ways, i.e. walkways, roadways, highways, and runways. My prior invention is illustrated and described in my U.S. Pat. No. 4,571,860, issued on Feb. 25, 1986 entitled Method and Apparatus for Removing Ice From Paved Surfaces.
The easy debonding, lifting, and removing of ice, originally tightly bonded to ways or pavements, as described in my patent, occurs when a vehicle is used, having, in an arrangement of selected special components from front to back, of a snow removal blade, a microwave energy emitting device and an ice scraper. In operation, as the vehicle passes over ice coated pavement, the snow is removed from the ice, microwave energy is directed, nearly transparently, through the ice to the pavement below the ice, creating heat to raise the temperature of the top surface of the pavement and thereby debond the ice. Then the ice is lifted and removed by the ice scraper from the pavement, as the debonded ice is easily lifted off of the surface of the pavement.
In my patent I then discussed two different types of pavements from which the ice could be debonded and then easily lifted and removed. One pavement is a portland cement concrete pavement topped by a protective reflective layer adhered to the concrete. Then a heat insulating material is adhered to this reflective layer. Thereafter a graphite containing epoxy top layer, is adhered to the heat insulating material. The other pavement was an asphaltic concrete or other type of an asphalt type pavement.
Although the objectives of this ice removal method and apparatus were reachable, there was a need to provide a better pavement at a comparatively lower cost to effectively and efficiently use the microwave energy to generate the heat to in turn debond the ice. During the time of determining this better pavement, and also during the considerations of these patent applications, information in many patents and publications has been reviewed. Some of this information considered pertinent is referred to as follows.
Mr. Jeppson in his U.S. Pat. No. 4,175,885 described his use of microwave energy to heat old asphaltic concrete pavement to restore it by raising the temperature so the asphalt cement would become liquid or semi-liquid.
Mr. Rostler in his U.S. Pat. No. 4,094,697 described his use of carbon black, in a range of seventy to one hundred parts by weight, in asphalt cement to increase the abrasion resistance of asphalt cement.
Messrs. Fukushima, Nozaki, Tanaka, and Kanegawa in their U.S. Pat. No. 4,008,095 described their addition of microgranular coal to asphalt to create a better paving composition.
Mr. Pickermann in his U.S. Pat. No. 4,276,093 described his asphalt production equipment utilizing microwave heaters.
Messrs. Boyko, Lederer and Sawyer reported, in March 1976, their use of a truck having microwave power generating equipment utilized during the patching of roadways. They described the use of their equipment for thawing and deicing applications. They said microwave energy will penetrate a sheet of ice on the surface of the concrete, with practically no loss. Then the microwave energy encounters the very highly absorbing material of water in the concrete, where it will be absorbed and dissipated in the form of heat. The temperature differential at the boundary of the ice and water saturated concrete causes separation of the ice from the concrete, and the ice can then be scraped and removed by conventional means.
Messrs. McLaughlin and Sayigh in their U.S. Pat. No. 4,032,355 described their bituminous composition for roadways, which they developed for use in hot climates.
Messrs, Dannenberg and Williams in their U.S. Pat. No. 4,196,013 described their oxidation resistant asphalt compositions. They dispersed in petroleum asphalt, oil furnace carbon black to improve the resistance of their newly formulated asphalt composition to thermal or actinic oxidation.
Mr. Brandon in his U.S. Pat. No. 4,370,534 described his use of microwave energy to heat, thaw, and/or demoisturize materials and/or objects.
Mr. Mouat in his U.S. Pat. No. 3,964,183 described his method and apparatus used for detaching coatings frozen on to surfaces, including paved roadways and runways. He provided equipment which directed a concentrated intense beam of visible light on to the interface between the coating and the surface to raise the temperature of the interfacial zone to the melting point, to free the coating from the surface.
In a West German patent 2,453,151, a method is described to decompose layers of ice from roads and rails by exposing the ice to electromagnetic waves of discrete narrow frequency bands. Then a mechanical device removed the ice.
Messrs. Osborne and Hutcheson in their U.S. Pat. No. 4,849,020 described their improved asphalt composite, which included a mixture of asphalt and a lossy microwave adsorptive material. By including this lossy microwave adsorptive material, they enhanced the removal, reconditioning, and reforming, of their improved asphalt composite, during patching or repair operations, which relied upon microwave radiation heating. Ferromagnetic material was the lossy microwave material, which was homogeneously mixed with the asphalt material. They listed four basic groups of substances used as lossy microwave material. The first group comprises semi-conductors such as zinc oxide. The second group comprises ferromagnetic materials. The third group comprises oxides of metal. The fourth group comprises dielectric materials, such as asbestos, carbon and graphite.